body {
    /* background: #f2f2f2; */
    background: #282c34;
}

.frame {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 400px;
    height: 400px;
    margin-top: -200px;
    margin-left: -200px;
    border-radius: 2px;
    box-shadow: 1px 2px 10px 0px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    background: #d33526;
    color: #fff;
}

.center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    perspective: 1500px;
}

.ball-big {
    position: relative;
    width: 200px;
    height: 200px;
    transform-style: preserve-3d;
    animation: ball 7s ease-in-out infinite;

    .plane {
        position: absolute;
        width: 200px;
        height: 200px;
        top: 0;
        left: 0;
        background: #fff;
        border-radius: 50%;
        opacity: 0.3;

        --degree: calc(30deg * var(--i));
        transform: rotateX(var(--degree));
    }
}

@keyframes ball {
    0% {
        transform: rotateY(0deg) rotateX(0deg) rotateZ(0deg);
    }
    25% {
        transform: rotateY(45deg) rotateX(180deg) rotateZ(20deg);
    }
    50% {
        transform: rotateY(225deg) rotateX(0deg) rotateZ(90deg);
    }
    75% {
        transform: rotateY(0deg) rotateX(45deg) rotateZ(120deg);
    }
    100% {
        transform: rotateY(0deg) rotateX(0deg) rotateZ(0deg);
    }
}
